Robert Fulton American engineer created the first operational steam-powered ship.
One of the oxoacids of nitrogen. Colourless, moderate acid with a pungent odour, that exists only in aqueous solution.
A compound formed as white smoke during the combustion of phosphorus.
The German triplane was perhaps the best known plane in World War I.
Schooners, first built in the Netherlands in the 17th century, were mainly used as merchant ships.
From the 1940s, the increasingly large aircraft carriers became the masters of the oceans.
A bireme is a type of ancient warship, with a characteristic pointed bow and two decks of oars, used by many armies.
Metals forming hexagonal metallic lattices are rigid and difficult to machine.
Colourless, moderate acid, only known in aqueous solution.
The face-centred cubic metal lattice allows the closest fit of metal atoms.
Farmhouses in the Middle Ages were simple, single-storey structures built from earth, mud and wood.
The Hubble Space Telescope orbits outside the distorting influence of Earth´s atmosphere.
DC motors consist of a permanent magnet and a coil within the magnet, with electric current flowing in it.
The Earth's continents have been in constant motion during the history of the planet.
A sphere is the set of points which are all within the same distance from a given point in space.
HMS Dreadnought revolutionised battleship-building in the 20th century.
This animation demonstrates various types of cylindrical solids as well as their lateral surfaces.
This animation demonstrates the components (vertices, edges, diagonals and faces) of the cube, one of the Platonic solids.
Ziggurats were typical terraced step pyramids used as temples in ancient Mesopotamia.
An exercise about the regular hexahedron built from unit cubes to help deepen your knowledge of cubes.
In alkaline batteries electric current is generated by electrochemical reactions